The composition and location of dust settled in supply air ducts.

The amounts, quality and factors affecting of dust accumulation in supply air ducts of eight nonindustrial buildings were studied. The average of surface density of dust settled in supply air ducts was 10.6 g/m² and the average of yearly accumulation rate was 3.5 g/m²*year. The dust contained 82% of inorganic material, which agrees well with the composition of outdoor air dust in down town areas. In straight air duct the surface density of settled dust decreased as a function of distance from the air handling unit (AHU).

Measurement of actual performances of ventilation systems in buildings.

Airtightness deficiencies of building envelopes and weaknesses in the ventilation systems can disrupt the operation of heating and ventilation systems. This can lead to an insufficient level of air quality and higher energy consumptions. In order to assess the performances of buildings and ventilation systems, CSTB has designed and developed different experimental devices for field testing. In a first step, an equipment was produced to measure the envelope air leakage. This apparatus is mainly used for research purposes.

Internal flow systems.

Mad air on the rise.

            

Code de calcul Multigaine.

           

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